Modules/RAMDisk - a bit more work

diff --git a/KernelLand/Modules/Filesystems/RAMDisk/ramdisk.c b/KernelLand/Modules/Filesystems/RAMDisk/ramdisk.c
index 9b6d2c0..309c842 100644 (file)
--- a/KernelLand/Modules/Filesystems/RAMDisk/ramdisk.c
+++ b/KernelLand/Modules/Filesystems/RAMDisk/ramdisk.c
@@ -32,7 +32,7 @@ size_t        RAMDisk_Write(tVFS_Node *Node, off_t Offset, size_t Size, const void *Buf
 // --- Internals --
 void   RAMDisk_int_RefFile(tRAMDisk_Inode *Inode);
 void   RAMDisk_int_DerefFile(tRAMDisk_Inode *Inode);
-void   *_GetPage(tRAMDisk_File *File, int Page);
+void   *_GetPage(tRAMDisk_File *File, int Page, int bCanAlloc);
 void   _DropPage(void *Page);
 
 // === GLOBALS ===
@@ -90,13 +90,23 @@ tVFS_Node *RAMDisk_InitDevice(const char *Device, const char **Options)
 
         int    n_pages = size / PAGE_SIZE;
        
-       rd = calloc(1, sizeof(tRAMDisk) + n_pages * sizeof(tPAddr));
+       rd = calloc(1, sizeof(tRAMDisk) + n_pages * sizeof(tPAddr) + n_pages / 8);
        rd->MaxPages = n_pages;
        rd->RootDir.Inode.Disk = rd;
        rd->RootDir.Inode.Node.ImplPtr = &rd->RootDir;
        rd->RootDir.Inode.Node.Flags = VFS_FFLAG_DIRECTORY;
        rd->RootDir.Inode.Node.Size = -1;
        rd->RootDir.Inode.Node.Type = &gRAMDisk_DirNodeType;
+       rd->Bitmap = (void*)&rd->PhysPages[ n_pages ];
+
+       for( int i = 0; i < n_pages; i ++ )
+       {
+               rd->PhysPages[i] = MM_AllocPhys();
+               if( !rd->PhysPages[i] ) {
+                       // Um... oops?
+                       break;
+               }
+       }
 
        return &rd->RootDir.Inode.Node;
 }
@@ -222,49 +232,64 @@ int RAMDisk_Unlink(tVFS_Node *Node, const char *Name)
 }
 
 // --- Files ---
-size_t RAMDisk_Read(tVFS_Node *Node, off_t Offset, size_t Size, void *Buffer)
+size_t _DoIO(tRAMDisk_File *File, off_t Offset, size_t Size, void *Buffer, int bRead)
 {
-       tRAMDisk_File   *file = Node->ImplPtr;
-        int    page_ofs;
-       char    *page_virt;
        size_t  rem;
+       Uint8   *page_virt;
+        int    page;
+
+       if( Offset >= File->Size )      return 0;
        
-       if( Offset >= file->Size )
-               return 0;
-       
-       if( Offset + Size > file->Size )
-               Size = file->Size - Size;
+       if( Offset + Size > File->Size )        Size = File->Size - Size;
 
-       if( Size == 0 )
-               return 0;
+       if( Size == 0 )         return 0;
 
-       page_ofs = Offset / PAGE_SIZE;
+       page = Offset / PAGE_SIZE;
        Offset %= PAGE_SIZE;
        rem = Size;
 
-       page_virt = _GetPage(file, page_ofs++);
-       if( Offset + Size <= PAGE_SIZE ) {
-               memcpy(Buffer, page_virt + Offset, Size);
-               return Size;
+       page_virt = _GetPage(File, page++, !bRead);
+       if(!page_virt)  return 0;
+       
+       if( Offset + Size <= PAGE_SIZE )
+       {
+               if( bRead )
+                       memcpy(Buffer, page_virt + Offset, Size);
+               else
+                       memcpy(page_virt + Offset, Buffer, Size);
+               return 0;
        }
        
-       memcpy(Buffer, page_virt + Offset, PAGE_SIZE - Offset);
+       if( bRead )
+               memcpy(Buffer, page_virt + Offset, PAGE_SIZE - Offset);
+       else
+               memcpy(page_virt + Offset, Buffer, PAGE_SIZE - Offset);
        Buffer += PAGE_SIZE - Offset;
        rem -= PAGE_SIZE - Offset;
        
        while( rem >= PAGE_SIZE )
        {
                _DropPage(page_virt);
-               page_virt = _GetPage(file, page_ofs++);
-               memcpy(Buffer, page_virt, PAGE_SIZE);
+               page_virt = _GetPage(File, page++, !bRead);
+               if(!page_virt)  return Size - rem;
+               
+               if( bRead )
+                       memcpy(Buffer, page_virt, PAGE_SIZE);
+               else
+                       memcpy(page_virt, Buffer, PAGE_SIZE);
+               
                Buffer += PAGE_SIZE;
                rem -= PAGE_SIZE;
        }
 
        if( rem > 0 )
        {
-               page_virt = _GetPage(file, page_ofs);
-               memcpy(Buffer, page_virt, rem);
+               page_virt = _GetPage(File, page, !bRead);
+               if(!page_virt)  return Size - rem;
+               if( bRead )
+                       memcpy(Buffer, page_virt, rem);
+               else
+                       memcpy(page_virt, Buffer, rem);
        }
 
        _DropPage(page_virt);
@@ -272,9 +297,22 @@ size_t RAMDisk_Read(tVFS_Node *Node, off_t Offset, size_t Size, void *Buffer)
        return Size;
 }
 
+size_t RAMDisk_Read(tVFS_Node *Node, off_t Offset, size_t Size, void *Buffer)
+{
+       tRAMDisk_File   *file = Node->ImplPtr;
+       
+       return _DoIO(file, Offset, Size, Buffer, 1);
+}
+
 size_t RAMDisk_Write(tVFS_Node *Node, off_t Offset, size_t Size, const void *Buffer)
 {
-       return 0;
+       tRAMDisk_File   *file = Node->ImplPtr;
+       
+       // TODO: Limit checks?
+       if( Offset == file->Size )
+               file->Size += Size;
+
+       return _DoIO(file, Offset, Size, (void*)Buffer, 0);
 }
 
 

diff --git a/KernelLand/Modules/Filesystems/RAMDisk/ramdisk.h b/KernelLand/Modules/Filesystems/RAMDisk/ramdisk.h
index 4692509..0765d08 100644 (file)
--- a/KernelLand/Modules/Filesystems/RAMDisk/ramdisk.h
+++ b/KernelLand/Modules/Filesystems/RAMDisk/ramdisk.h
@@ -55,6 +55,7 @@ struct sRAMDisk
        tRAMDisk_Dir    RootDir;
        
         int    MaxPages;
+       Uint32  *Bitmap;
         int    nUsedPages;
        tPAddr  PhysPages[];
 };